Surface treating apparatus



ug. I@ 1938. A. o. ENGBERG 2,126,761

SURFACE TREATING APPARATUS Filed March .28,` 1955 2 sheets-sheet 1INVENTOR B'Y www;

/v a ATTORNEY Aug w, 193s. n A. o. ENGBERG 2,126,761

SURFACE TREATING APPARATUS Filed March 28, 1955 A 2 Sheets-Sheet 2Pnenfed Aug. 16, 193s PATENT ori-ice SURFACE TREATING APPARATUS AxelOlot Engberg, Stockholm, Sweden, assigner to Aktiebolaget Elektroiux,Stockholm, Sweden, acorporation of Sweden Application March 28, 1935,Serial No. 13,567

In Germany March 29, 1934 l 9 Claims.

My invention relates to surface treating apparatus and more particularlyto electrically driven apparatus of this kind adapted to treat floors,Windows and the like. In apparatus of this kind 5 the power often istransmitted from the driving motor to the members carrying theimplements for treating the' surfaces by a friction gearing. Between thedriving pinion connected to the motor shaft and the discs in suchmachines there l must be a certain amount of resiliency so as to ensurethe necessary frictional pressure between the rotating parts.

In previous apparatus of this kind this frictional pressure was obtainedby arranging the l discs movably in the frame of the apparatus againstan elastic pressure or by pivotally connecting them by pin joints to theframe. Such apparatus are however not only complicated and consequentlyexpensive in manufacture buttheir bearings are also subjected to heavyvibrations from the motor rotating at a high speed. According to theinvention these disadvantages are removed by supporting the carriers forthe said implements in stationary manner relative to their carryingframe and ensuring the frictional pressure between the discs and thefriction pinion, or between the discs themselves, by the construction orthe selection of the material of the frame and/or the carriersthemselves.

A further object of the invention is to equip the frame with slots orthe like in such a way that resilient arms are formed in which thecarriers areV journalled.

A still further object of the invention resides in providing thecarrying discs themselves with a ring-shaped member of elastic material,or a ring-shaped part of the disc may be resilient, due to theconstruction of this part.

The nature of the invention will become apparent from the followingdescription taken in conjunction with the accompanying drawings formingpart of the specification which show a preferred surface treatingapparatus embodying -the invention. Of the drawings Fig. 1 is asectional view of a surface treating -apparatus according to theinvention and provided With three carriers for surface treatingimplements;

Fig. 2 is a section of the sameA apparatus along the line II-II in Fig.1;

Fig. 2a isa sectional view taken on the line lIa-IIa of Fig. 2;

Fig. 3 is a View partly in section of a further embodiment of a surfacetreating apparatus ac- .li cording to the invention and provided with asingle carrier only;

Fig. 4 is a sectional view taken on the line IV-IV of Fig. 3; and

Figs. 5-8 show various embodiments of ro 5 tatable implement carrierswhereby the carriers themselves are arranged or constructed to producethe necessary resilientv frictional pressure.

In the surface treating machine according to Figs. 1 and 2 the drivingmotor is enclosed by a l0 casing I0. The motor rests on a frame IIconsisting, for example of cast-iron on the underside of which brushdisc carriers I2 and I3 are supported. 'I'hershaft of the motor isdesignated by I4 and is formed at its lower end into a friction "l5pinion I4. The frame II and the brush discs are covered by a hood I5preferably made of sheet aluminium or of any cast metal. As shown inFig. 2, the frame II is provided with slot I6 so that bent arms I1 areformed. In these arms the' 20 two discs I2 bearing on the frictionpinion I4 are journalled. while the front disc I3 is journalled in thatpart of the frame which has no slots.

Owing to the form of the slots I6 the arms I1 will be resilient to acertain degree, and careful 25 investigations have shown that thisself-resiliency of the frame is sufficient to ensure the necessaryfrictional pressure between the discs I2 and the friction pinion on theone hand and between the discs I2 and I3 on the other hand. It 30 isevident that in the manufacture and mounting of the surface treatingmachine the distances between the axis of the friction pinion and theaxes ofthe rotating discs must be dimensioned in such a way that thedesired frictional pres- 35 `sures are ensured by the spring action ofthe arms II. In order to prevent an undesirable distortionl of the armsI1 in any direction other than in a plane perpendicular to the axis ofshaft I4, pins or the like I8 are, as shown in Fig. 2, 40 fixed in therigid central part of the frame, which pins have sliding engagement inguides or apertures in the outer ends of the arms I1. These guidingdevices permit movement of the ends of arm I'I' in a plane perpendiculartothe axis of 45 shaft I4', but prevent the frictional pressure betweenthe discs I2 and I3 from being reduced appreciably owing to anundesirable bending .of the arms I'I. Y'

Figs. 3 and 4 show a modied embodiment of a 50 surface treating machinein which only a single carrier I2 for a surface treating disc is used.In other respects the construction is the same as that previouslydescribed. In order to relieve the strain on the rear part of thesurface treating 5I machine rollers i9 are provided under the drivingmotor, the supporting points of these rollers forming together withthepoints of the brushes the supporting surface of the apparatus.

In the embodiments desciibed the frlctional pressure between thedifferent rotating parts 'is produced by the form oi the frame in whichthe brush discs are journalled. According to the invention it is howeveralso possible to give the brush discs themselves the necessaryfrictional pressure by a suitable construction or by -the use ofsuitable materials. In Fig. 5 a ring-shaped member 2l of corrugatedsheet metal or the like is inserted between the hub 20 of the disc andits periphery. This annular corrugation of the ring-shaped intermediatemember 2| gives the necessary resiliency for the desired frictionalpressure. In Figs. 6 and 7 a corrugated sheet metal ring or the like 24is inserted between the periphery 22 and the inner rigid part 23 of thedisc in order to ensure the necessary spring action. In Fig. 8, finally,a thick rubber ring 21 is inserted between the hub 20 of the disc andits outer rigid part, which rubber ring gives the necessary resiliency.Under certain circum stances the methods described for obtaining thedesired frictional pressure may also be applied in any desiredcombination. Y

What I claim is:

1. In a floor polisher, a frame having integral parts. a driving shaftrotatable about an axis fixed with respect to a part of said frame, apin rigidly fixed to another part of said frame, a brush carrier memberhaving a hub rotatably mounted on said pin and having a. rigid circularedge, the hub of said brush carrier member being permanently concentricwith said pin, and resilient means arranged in the path of forcetransmission between the first mentioned part of said frame and saidedge for resiliently urging said edge toward said driving shaft.

2. A device as claimed in claim 1 in which a resilient tire isinterposed between said rigid edge and said driving shaft.

3. A device as claimed in claim l in which a resilient tire is carriedby said rigid edge for frictional engagement with said driving shaft.

4. In a floor polisher, an integral frame includinga rigid main part anda resilient arm, a driving shaft rotatable about an axis xed withrespect to said main part, and a circular brush carrier member rotatablymounted on said arm, said carrier member being urged into rotatingengagement with said driving shaft by the resiliency of said arm.

5. A device as claimed in claim 4 including a rigid pin secured to saidmain part and having sliding engagement with said arm in a planeperpendicular to the axis of said driving shaft for preventingdistortion of said arm in a direction at an angle to said plane.

6. In a floor polisher, an integral frame including a rigid main partand a pair of resilient arms, a driving shaft rotatable about an axisfixed with respect to said main part, a first circular brush carriermember rotatably mounted on said main part, and a circular brush carriermember rotatably mounted on each of said arms, said last-mentionedcarrier members being urged into rotating engagement with said drivingshaft and with said rst carrier member by the resiliency of said arms.

'7. n a ioor polisher, a rigid frame having integral parts. a drivingshaft rotatable about an axis xed with respect to a part of said frame,'a pin rigidly xed to another part of said frame, and a brush carriermember rotatably mounted on said-pin and including a hub, a

rigid circular edge and resilient means between said hub and said edgefor urging said edge toward said driving shaft, said hub beingpermanently concentric with said pin.

8. A device as claimed in claim 7 in which said resilient meanscomprises a rubber ring.

9. A device as claimed in claim 7 in which said resilient meanscomprises a corrugated disc of metal.

AXEL OLOF ENGBERG.

